2 Fever PhobiaFever is the most common pediatric complaint, second only to routine care for clinic visits, and the most common reason kids are brought to the ER.In the Middle Ages, fever was felt to be a marker of death or divine punishment.Some feel true fever is harmful: 1/3 parents thought 38-40ºC( ºF), 2/ ºC( ºF), and all thought brain damage >41ºC(106ºF).5-20% have no localizing signs on PE with no history to explain the fever.The majority of kids with fever do not have a serious illness, although a small percentage harbor or may develop a serious bacterial infection.True fever is not harmful to a child if the fever is not due to a serious infection and the temperature elevation is not due to excess heat load, defective heat loss mechanism, CNS damage or disease, or excess heat production.

3 ‘True’ FeverOccurs when IL-1, IL-6, TNF-ά or other cytokines are released from monocytes and macrophages in response to infection, tissue injury, drugs, and other inflammatory processes, increasing the body’s set point. The anterior hypothalamus maintains an inherent set point near 36ºC(98.6ºF).Normal circadian rhythm, which is highest(up to 2ºC, 3ºF) ~6pm and lowest at 6am. This accounts for increased volume of ER visits that peaks in the evening. Most true fevers follow this diurnal pattern.

4 ‘False’ fever, aka hyperthermiaDoes not directly increase the body’s set point.CNS disease that directly affects the hypothalamus--ICH, infection.Diseases that increase the body’s production of heat--hyperthyroidism, malignant hyperthermia, salicylate overdose.Excess heat load--child left in a car or left next to a heater for too long.Defective heat loss mechanisms--burns, heat stroke, drugs that compromise blood flow and sweating mechanisms.Normal causes of temperature elevation include physical activity, ovulation, and environmental temperature.

5 Reliable Temperature MeasurementAll measurements are estimates of the body’s true core temp—central circulation=aorta and pulmonary artery.RECTAL—gold standardEsophageal—accurate but impracticalTactile and axillary—inaccurate, varies considerably with environmental temperatureTympanic—inaccurate in age <3 years

6 Benefits of feverThe hypothalamus will not allow the temp to rise above 41.5ºC(107ºF).WBCs work best and kill the most bacteria at 38-40ºC( ºF).Neutrophils make more superoxide anion, and there is more and increased activity of interferon.Coxsackie and polio virus replication is directly inhibited.

7 Fever without a source(FWS)5 to 20% of febrile children have no localizing signs on PE and nothing in the history to explain the fever. By definition, less than 7 days.FWS(like fever) is most common in children younger than age 5, with a peak prevalence between 6 and 24 months of age.Those <6 months retain protective maternal antibodies against common organisms, while those months old are more immune competent, and are at a lower risk of developing bacteremia

8 Diagnostic Assessment in ChildrenAge is important as 1) etiologic pathogens, 2) clinical exam, and 3) immune system capacity changes as the newborn ages.Most break them into the first 2-4 weeks of life(neonatal), 1-3 months, and 3 to 36 months.

9 NeonatalPE is felt to be unreliable in detecting many serious bacterial infections. Meningitis should always be considered—up to 10% appear well, only 15% have a bulging fontanelle, and 10-15% have nuchal rigidity. So, a high index of suspicion is important!!! ~20% will not have fever initially.Hyperthermia or hypothermiaLethargy or irritabilityPoor feeding or vomitingApneaDyspneaJaundiceHypotensionDiarrhea or abdominal distensionBulging fontanelleseizures

10 NeonatesThe majority of febrile neonates presenting to the ED have a nonspecific viral illness12% have serious bacterial infections (SBI)Infected by more virulent bacteriaMore likely to develop serious sequelae from viral infectionsGBBS is associated with high rates of meningitis(39%), non-meningeal foci(10%), and sepsis(7%)The most common bacterial infections are UTI and occult bacteremia

14 Infants 1 to 3 months CausesHSV(17% are 15 days to 6 weeks of age)Bacterial sepsis/meningitisGroup B Strep, S. Pneumoniae, H. influenza, N. meningitidis, EnterobacteriaceaeBone and joint infectionsUTIBacterial enteritis(esp Salmonella)PneumoniaEnterovirus sepsis/meningitis(July-October)The risk of bacteremia/meningitis is 3.3%, pneumonia, bone/joint infections and bacterial enteritis is 13.7%30-50% of those who are ultimately diagnosed with bacterial meningitis have been seen by a physician within the prior week(usually 1-2 days before) and were diagnosed as having a trivial illness and discharged on oral antibiotics.These children may have had early meninigitis that was missed or occult bacteremia that progressed to meningitis.

17 Infants 1 to 3 monthsInfants who are toxic and febrile have a much higher risk of serious bacterial infection. They should be admitted, have a full sepsis workup, and given antibiotics/antiviralsAmpicillin and Cefotaxime.Infants who are nontoxic and febrile who meet all Rochester criteria can ‘safely’ be treated as an outpatient. Generally, 1-2.9% of children meeting these criteria will develop a serious bacterial infection, 0.7% bacteremia, 0.14% meningitis.

19 Infants 1 to 3 monthsIf all of the criteria are met, then there are 2 options for outpatient management:1) Blood, Urine Cultures, LP, Ceftriaxone 50mg/kg IM (to 1g), and return for reevaluation within 24 hours.2) Blood, Urine Cultures and careful observation.Parents should have mature judgement, can return within 30 minutes and have a thermometer and a phone.IF NO LP IS DONE, DO NOT GIVE CEFTRIAXONE AS IT WILL COMPROMISE F/U IF THE PATIENT IS STILL FEBRILE

21 Heptavalent pneumococcal conjugate vaccine, PCV7(Prevnar)Licensed in February 2000Routinely incorporated into the childhood immunization schedule in mid-20004, 6B, 9V, 14, 18C, 19F, 23FRecommended for all children aged 2 to 23 monthsInvasive pneumococcal disease in children younger than 2 years has decreased by at least 60%.

23 Rates of Invasive Pneumococcal Disease by Age Group and YearThe mean rate of IPD decreased0-30 days 39%31-60 days 45%61-90 days 32%The rate of IPD among infants aged 0 to 60days decreased from 7.3 per 100,000 to 4.2 per 100,000

24 Rates of Invasive Pneumococcal Disease Caused by PCV7 and Non-PCV7 Serotypes in Neonates and Young Infants Aged 0 to 90 Days by Study YearMean rate 7.3 to 2.4

25 So what?This data is the first to suggest that neonates and infants too young to receive PCV7 are benefiting from herd immunity.One hypothesis is that vaccinated children are less likely to have nasal carriage of pneumococcus.

27 Infants 3 to 36 monthsUA with micro, CBC with differential, Blood CulturesLP if meningeal signs, not wanting to be held or moved, petechiae, purpura or toxic.Antimicrobials:OM or pneumonia: cover for pneumococcus, non-typable H. flu and Moraxella: amoxicillin+augmentin, ceftriaxoneURI or no focus: cover for pneumococcus and menigococcus: amoxicillin(80-100mg/dg/day), ceftriaxonePneumococcemia: promptly reassess, if well, should at least treat with 1 dose ceftriaxone.PCV-7 >97% protection, thus all pneumococcal sepsis will decrease by 90%. So CBC and antimicrobials for this age group is becoming less critical.Toxicity assessment: loss of alertness, decreased activity, irritability, higher fever, sustained fever, anorezia, vomiting, pallor, grunting, and maternal worry.

28 Occult Bacteremia 5% of children with FWS have OCCULT BACTEREMIAThe presence of a positive blood culture in kids who look well enough to be treated as outpatients and in whom the positive results are not anticipated.

29 Occult BacteremiaStreptococcus pneumonia is responsible for 2/3 to ¾ of all cases.Peak prevalence between 6 and 24 monthsAssociation with high fever(39.4ºC or 103ºF)High WBC count(>15,000)Absence of evident focal soft tissue infection.Neisseria meningitidis, Haemophilus influenzae type b, and salmonellae account for most of the remaining cases.

30 Risk of Occult BacteremiaLow RiskAge >3yrTemp <39.4ºCWBC >5000 and <15,000High Risk<2yr>40ºC(104ºF)<5000 or >15,000Hx of contact with H. Flu or N. meningitidisOB has a low prevalence, so even though WBC is a sensitive and specific screening test, it has a low PPV. So the test does not discriminate between children who have FWS who are bacteremic and those who are not.Therefore, blood culture is the gold standardstill has a high number of false positives, take 24-48hrs, and most cases of occult pneumococcal bacteremia clear without treatment.